Colorado will update its mask order “shortly,” a spokeswoman for Gov. Jared Polis said Thursday night, hours after the Centers for Disease Control and Prevention announced that fully vaccinated people largely don’t need to wear face coverings indoors.

The CDC released the masking guidance Thursday, which prompted President Joe Biden to declare it “a great day for America.” Though the new recommendations still call for masking in crowded indoor settings like jails, buses, planes and hospitals, they clear the way for people who have been fully inoculated to ditch masks in schools, offices, restaurants and other indoor settings. It’s the most significant step yet in signaling a return to a degree of pre-pandemic normalcy, bolstered by vaccine uptake nationwide, dropping infection rates and studies showing the strong efficacy of vaccinations.

Colorado’s mask mandate has been whittled down over the past month, as vaccination rates here increase and the mortality rate drops. As it stands Thursday, masks aren’t required in

doors when 80% of occupants have been vaccinated or when there are fewer than 10 people, regardless of their vaccination status.

Shelby Wieman, spokeswoman for Polis, said the state “will be updating our mask order to follow CDC guidance shortly.” She did not respond to a follow up email asking for a more specific timeline.

At a press conference Thursday, Eric France, Colorado’s chief medical officer, said he’d been in back-to-back meetings and hadn’t had a chance to discuss the CDC’s new recommendations with Rachel Herlihy, the state’s epidemiologist.

But he said health officials “in general will be reviewing” the new guidance and “looking at how it impacts our own masking guidelines.” But it’s too early to “say anything just yet” about the implications of the new recommendations on Colorado.

“I’m certain that after we have a chance to review this, we’ll look at how it impacts our own Colorado mask recommendations,” he said.

Asked about the timeline for this review and any changes, France said it will “be within the coming days.”

Herlihy, who also spoke at the press conference, emphasized that the new vaccine guidance only applies to fully vaccinated people. Currently, fewer than 50% of Coloradans have been inoculated; that number decreased this week, thanks to the federal government approving vaccine administration for adolescents between the ages of 12 and 15.

“There are still going to continue to be many children who aren’t fully vaccinated for quite a while,” Herlihy said.

Indeed, during the most recent fourth pandemic wave, which Herlihy said is beginning to subside, teenagers have tallied the highest rate of infection.

Glen Mays, a professor and department chair at the Colorado School of Public Health, said in an email that changing the masking recommendations was “a logical step.”

“In light of what we know about the effectiveness of the vaccines, there should be no need to maintain masks and distancing recommendations for vaccinated people,” he wrote. “This should help to eliminate a perceived inconsistency in public health recommendations and hopefully inspire even more confidence and urgency around vaccination as the road to the end of the pandemic.”

At a press conference earlier in the day Thursday, CDC officials praised the new guidance as a significant step toward returning the United States to some degree of pre-pandemic normalcy. Rochelle Walensky, the CDC’s director, said Americans had “longed for this moment.”

Walensky said the long-awaited change is thanks to the millions of people who have gotten vaccinated and is based on the latest science about how well those shots are working.

“Anyone who is fully vaccinated can participate in indoor and outdoor activities — large or small — without wearing a mask or physically distancing,” Walensky said. “If you are fully vaccinated, you can start doing the things that you had stopped doing because of the pandemic.”

The new guidance is likely to open the door to confusion, since there is no surefire way for businesses or others to distinguish between those who are fully vaccinated and those who are not. Walensky said those who are not fully vaccinated should continue to wear masks indoors.

In Colorado, when the mask order adjusted to its current level, state officials said restaurants and other businesses could verify themselves if enough of their customers are vaccinated to allow face coverings to be removed.

To date, more than 5 million doses have been doled out in Colorado; more than 2.7 million residents have received at least one dose, and more than 2.2 million are fully inoculated. Nationwide, roughly 154 million Americans — more than 46% of of the population — have received at least one dose.

Both in Colorado and nationwide, the rate of new vaccinations has slowed in recent weeks, though state and federal officials have said they anticipate an uptick now that adolescents have been cleared to receive the Pfizer shot.

The CDC’s new guidance is a reversal from just two weeks ago, when the agency recommended that fully vaccinated people continue to wear masks indoors in all settings and outdoors in large crowds.

Walensky said evidence from the U.S. and Israel shows the vaccines are as strongly protective in real world use as they were in earlier studies, and that so far they continue to work even though some worrying mutated versions of the virus are spreading.

The more people continue to get vaccinated, the faster infections will drop — and the harder it will be for the virus to mutate enough to escape vaccines, she stressed, urging everyone 12 and older who’s not yet vaccinated to sign up.

And while some people still get COVID-19 despite being vaccinated,

“If you are fully vaccinated, you can start doing the things that you had stopped doing because of the pandemic.”

Rochelle Walensky, CDC director

Walensky said, that’s rare. She cited evidence that those infections tend to be milder, shorter and harder to spread to others. If people who are vaccinated do develop COVID-19 symptoms, they should immediately put their mask back on and get tested, she said.

There are some caveats. Walensky encouraged people who have weak immune systems, such as from organ transplants or cancer treatment, to talk with their doctors before shedding their masks. That’s because of continued uncertainty about whether the vaccines can rev up a weakened immune system as well as they do normal, healthy ones.

The new guidance had an immediate effect at the White House, which has taken a cautious approach to easing virus restrictions. Staffers were informed that masks are no longer required for people who are fully vaccinated. And Biden, who was meeting with vaccinated Republican lawmakers in the Oval Office when the guidance was announced, led the group in removing their masks Thursday afternoon.